The Collaborative International Dictionary of English v.0.48:

Vary \Va"ry\, v. t. [imp. & p. p. Varied; p. pr. & vb. n.
   Varying.] [OE. varien, F. varier, L. variare, fr. varius
   various. See Various, and cf. Variate.]
   [1913 Webster]
   1. To change the aspect of; to alter in form, appearance,
      substance, position, or the like; to make different by a
      partial change; to modify; as, to vary the properties,
      proportions, or nature of a thing; to vary a posture or an
      attitude; to vary one's dress or opinions.
      [1913 Webster]

            Shall we vary our device at will,
            Even as new occasion appears?         --Spenser.
      [1913 Webster]

   2. To change to something else; to transmute; to exchange; to
      alternate.
      [1913 Webster]

            Gods, that never change their state,
            Vary oft their love and hate.         --Waller.
      [1913 Webster]

            We are to vary the customs according to the time and
            country where the scene of action lies. --Dryden.
      [1913 Webster]

   3. To make of different kinds; to make different from one
      another; to diversify; to variegate.
      [1913 Webster]

            God hath varied their inclinations.   --Sir T.
                                                  Browne.
      [1913 Webster]

            God hath here
            Varied his bounty so with new delights. --Milton.
      [1913 Webster]

   4. (Mus.) To embellish; to change fancifully; to present
      under new aspects, as of form, key, measure, etc. See
      Variation, 4.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Varying \Va"ry*ing\,
   a. & n. from Vary.
   [1913 Webster]

   Varying hare (Zool.), any hare or rabbit which becomes
      white in winter, especially the common hare of the
      Northern United States and Canada.
      [1913 Webster]

WordNet (r) 3.0 (2006):

varying
    adj 1: marked by diversity or difference; "the varying angles of
           roof slope"; "nature is infinitely variable" [syn:
           varying, variable]

Moby Thesaurus II by Grady Ward, 1.0:

90 Moby Thesaurus words for "varying":
   assorted, at odds, at variance, capricious, changeable, changing,
   choppy, contrary, contrasted, contrasting, departing, deviating,
   deviative, deviatory, different, differentiated, differing,
   disaccordant, disagreeing, discordant, discrepant, discrete,
   discriminated, disjoined, disorderly, disparate, dissimilar,
   dissonant, distinct, distinguished, divaricate, divergent,
   diverging, divers, diverse, diversified, diversiform, erose,
   erratic, heterogeneous, impulsive, in disagreement, inaccordant,
   incompatible, incongruous, inconsistent, inconsonant, inconstant,
   inharmonious, irreconcilable, irregular, jagged, jerky, many,
   mercurial, motley, multifarious, mutable, nonconformist,
   nonstandard, nonuniform, pluralistic, poles apart, poles asunder,
   ragged, rough, separate, separated, several, spasmodic, sporadic,
   unconformable, unequable, unequal, uneven, unlike, unorthodox,
   unstable, unsteady, unsystematic, ununiform, variable, variant,
   varied, variegated, variform, various, wavering, widely apart,
   worlds apart